Don Carson shows that the term ‘son of God’ has a range of meanings in the Bible. The phrase ‘son of’ can mean biological offspring, but it can be used metaphorically to mean non-biological relationships or similarities. ‘Son of Belial’ (translated in a variety of ways such as ‘worthless men’) describes people who share the nature of wickedness. So when Paul says Christians are ‘sons of Abraham’ he is not saying we are his biological offspring, but that we share a characteristic of Abraham (in this case, his faith). With this in mind we can see how angels can be called ‘sons of God’ (since they share God’s holiness) or how Adam could be called a ‘son of God’ (since he is made in God’s likeness) or how peacemakers can be called ‘sons of God’ (since they share God’s peaceable character).

When Jesus is described as ‘the son of God’ it can mean that:

he is the true messianic King (via 1 Samuel 7 and Psalm 2)

he is the true Israel (the son of God as Israel was called to be the son of God)

he is the true humanity (the son of God as Adam was to be the son of God)

he is the pre-existent Son of God

(It might have been helpful to have more on how these co-ordinate expanding on how the Messiah is the representative of Israel which in tern is the representative of humanity.)

Carson’s distinctive contribution is to show how these senses all feed into one another. So in some key texts (chapter two focuses on Hebrews 1 and John 5) they mutually interpret one another or resonate with one another so that these different senses cohere and combine. Carson says: ‘Judging by the evidence of Hebrews 1 … Christians commonly plugged away at integrating confessional christologies. Just as we discovered … that Matthew can leap from an Israel-as-Son-of-God christology to a Davidic-king-as-Son-of-God christology, showing no embarrassment at affirming that Jesus is the Son of God in both senses, so Hebrews 1 leaps from preexistent-Godhead-as-Son-of-God christology to Davidic-king-Messiah-as-Son-of-God christology. (61-62) ‘The richest theological loading of the expression “Son of God” as applied to Jesus springs from passages that deploy the expression to cross-pollinate distinctive uses.’ (107)

In chapter 3 Carson draws conclusions from this foundational material. After drawing some general conclusions, he considers the recent argument that alternative terms to ‘Father’ and ‘Son’ should be used to translate the Bible in Muslim contexts where such language may be misunderstood as biological, creating an unnecessary barrier to the gospel. Carson rejects this argument for a variety of reason, one of which is his earlier conclusion that the different senses of ‘Son of God’ come together in the trajectories of Scripture. Carson relates the challenge of translating ‘lamb of God’ in a culture that sacrifices pigs. Should it be translated ‘swine of God’? Taken on its own there would be a good case of this. But readers would soon encounter other biblical texts that talk of flocks of sheep or texts that designate pork as unclean. The initial easy fix generates bigger problems elsewhere. So it is better to translate it as ‘lamb of God’ and provide explanations. In the same way, it might be acceptable to translate isolated references to a phrase like ‘sons of a quiver’ as ‘arrows’, but ‘son(s) of God’ is a very different issue. ‘On almost any reading of the evidence, the associations of the expression are complicated, theological laden, and inescapable. Why should it not be better, then, to render the original more directly, perhaps with explanatory notes?’ (93)

Moreover the Muslim world is not unique in having no ready referent for eternal sonship. ‘No language, no culture means by “Son” what Jesus means in John 5 – yet “Son” is the category Jesus uses, even though nothing in English, or Urdu, or Arabic, prepares us for a Son of God whose relationship with the Father is anything like what the text describes.’ (103) John 5:26, for example, says: ‘For as the Father has life in himself, so he has granted the Son to have life in himself.’ What does Jesus mean when he asserts that the Father has ‘granted’ him life and that he has ‘life in himself’? Carson concludes: ‘The best explanation is the old one: this is an eternal grant. It is not a grant given to Jesus at some point in time, as if before that point he did not have life-in-himself. After all, John has already insisted that the pre-incarnate Word had life in himself (1:4), Thus John 5:26 helps to establish the peculiar relationships between the Father and the Son, in eternity and form eternity. It is an eternal grant.’ (69)

This book is a response to this debate, but it is more than this: it is an attempt to delineate and co-ordinate the different uses of the term ‘son of man’.